*/
    protected void extractFrontMatterMetadata(final Node document, final ExtractData extractData) {
        final YamlFrontMatterVisitor visitor = new YamlFrontMatterVisitor();
        document.accept(visitor);

        final Map<String, List<String>> frontMatter = visitor.getData();
        for (final Map.Entry<String, List<String>> entry : frontMatter.entrySet()) {
            final String key = "frontmatter." + entry.getKey();

        accessResult.setUrl("https://example.com/visited");
        accessResultMap.put("https://example.com/visited", accessResult);

        UrlQueueImpl<Long> newUrl = new UrlQueueImpl<>();
        newUrl.setSessionId(sessionId);
        newUrl.setUrl("https://example.com/new");

        UrlQueueImpl<Long> visited = new UrlQueueImpl<>();
        visited.setSessionId(sessionId);
        visited.setUrl("https://example.com/visited");

    limiter.acquire(Integer.MAX_VALUE / 4);
    limiter.acquire(Integer.MAX_VALUE / 2);
    limiter.acquire(Integer.MAX_VALUE);
    assertEvents("R0.00", "R0.00", "R0.00");

    limiter.setRate(1.0);
    limiter.acquire();
    limiter.acquire();
    limiter.acquire();
    assertEvents("R0.00", "R1.00", "R1.00");

    limiter.acquire(Integer.MAX_VALUE / 4);
    limiter.acquire(Integer.MAX_VALUE / 2);
    limiter.acquire(Integer.MAX_VALUE);
    assertEvents("R0.00", "R0.00", "R0.00");

    limiter.setRate(1.0);
    limiter.acquire();
    limiter.acquire();
    limiter.acquire();
    assertEvents("R0.00", "R1.00", "R1.00");

    # since we're creating a new limiter for each call, any non-zero limit
    # works (1 is arbitrary)
    exit_limiter = CapacityLimiter(1)
    try:
        yield await run_in_threadpool(cm.__enter__)
    except Exception as e:
        ok = bool(
            await anyio.to_thread.run_sync(
                cm.__exit__, type(e), e, e.__traceback__, limiter=exit_limiter
            )
        )
        if not ok:

    )


def get_flat_dependant(
    dependant: Dependant,
    *,
    skip_repeats: bool = False,
    visited: Optional[list[DependencyCacheKey]] = None,
    parent_oauth_scopes: Optional[list[str]] = None,
) -> Dependant:
    if visited is None:
        visited = []
    visited.append(dependant.cache_key)
    use_parent_oauth_scopes = (parent_oauth_scopes or []) + (
        dependant.oauth_scopes or []
    )

        // TODO use cache
    }

    /**
     * Checks if a URL has been visited by looking in both the queue and access results.
     *
     * @param urlQueue The URL queue entry to check.
     * @return true if the URL has been visited, false otherwise.
     */
    @Override
    public boolean visited(final OpenSearchUrlQueue urlQueue) {
        final String url = urlQueue.getUrl();

                return null;
            }

            @Override
            public void saveSession(String sessionId) {
            }

            @Override
            public boolean visited(UrlQueue<?> urlQueue) {
                return false;
            }

            @Override
            public void generateUrlQueues(String previousSessionId, String sessionId) {
            }
        };

        }
        try {
            final FilePurgeVisitor visitor = new FilePurgeVisitor(baseDir.toPath(), imageExtention, expiry);
            Files.walkFileTree(baseDir.toPath(), visitor);
            return visitor.getCount();
        } catch (final Exception e) {
            throw new JobProcessingException(e);
        }
    }

    /**
     * File visitor for purging old thumbnail files.
     */

    return () ->
        new Iterator<T>() {
          private final ListIterator<T> listIter = list.listIterator(list.size());

          @Override
          public boolean hasNext() {
            return listIter.hasPrevious();
          }

          @Override
          public T next() {
            return listIter.previous();
          }

          @Override
          public void remove() {